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    Re: chronometer dials: 12 or 24 hours?
    From: Clive Sutherland
    Date: 2009 Jan 19, 22:29 -0000

    Thanks George;
    For your interest there is a similar one at Edinburgh Observatory from which
    time signals are sent to trigger the famous 1 o'clock Gun at Edinburgh
    castle.
    The roman numerals are a pain but the dial is as I described with the hour 1
    representing 2.5 minutes, the integer minutes are quite clear to read
    provided you are used to the 60 min dial. 
    Do you recall if the minute hand jumps instantly from one mark to the next
    as the second hand on the separate dial changes from 59 to 60 ? or is the
    indication true analogue.
    
    Clive.
     
    
    > -----Original Message-----
    > From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf
    > Of George Huxtable
    > Sent: 19 January 2009 21:47
    > To: NavList@fer3.com
    > Subject: [NavList 7118] Re: chronometer dials: 12 or 24 hours?
    > 
    > Oops!Sorry, forgot to add the attachment. Try again.
    > 
    > ===========================
    > 
    > The attached picture should answer Clive's worry about the difficulty of
    > reading a 24-hour clock. This clock has stood at a gate of the Royal
    > Observatory, Greenwich, for over 150 years. It's actually an early
    > electric
    > "repeater" from a master clock.
    > 
    > In my view, the only problem about reading it is in the multiplicity of
    > Is,
    > Vs, and Xs that are called for by the use of Roman numerals. If ordinary
    > numerals had been used, it would have been much clearer.
    > 
    > It relates, a bit, to earlier discussion, in that the moment of passing 24
    > hours must have been changed, at some date, from midday to midnight.
    > Probably when Greenwich time changed, at the start of 1924.
    > 
    > Note that at the very top mark, the dial is not labelled XXIV (=24), but
    > 0,
    > something that all our 12-hour dials could usefully follow.
    > 
    > George.
    > 
    > contact George Huxtable, at  george{at}hux.me.uk
    > or at +44 1865 820222 (from UK, 01865 820222)
    > or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    > 
    > > 
    > 
    > No virus found in this incoming message.
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    > Version: 8.0.176 / Virus Database: 270.10.9/1902 - Release Date: 1/19/2009
    > 9:37 AM
    
    
    
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